Saturday, June 18, 2011

Engineer's Report from Stone

The bus was in really good condition when we bought it, considering it was built way back in 1973 (in Germany). The main killer of old VWs - rust - was only present in a few inconsequential surface areas on the body, which we figure we'll fix in Detroit when we do a respray. The engine ran smoothly (it was rebuilt 20k before we got it), with the main niggle being a difficult to get 2nd gear, especially changing down. Double clutching whilst braking remains a skill we both have to get a handle on. The bus of course also leaked a bit of oil and 'marks its spot' when parked.

Handling
But, when we started driving it on our initial 1 night exploratory camping adventures near Houston, we noticed how bad the thing handled on the highway. Top speed was effectively 55mph max while constantly struggling to keep the thing on the road. With even a mild cross wind this dropped to 45mph (at most) because the bus would be pushed around sideways several feet and it was waaay too scary to go any faster, for fear of suddenly being sent into either on-coming traffic or the ditch by the side of the road. Several times we had to get off the freeway, because being passed by everything else on the road while struggling to keep 45 mph was too dangerous.

A search of the Samba and other on-line resources suggested new shocks and heavy duty anti-sway bars were the key and offered hope of ensuring we could actually get from Houston to Detroit faster than it would take to walk it. So that's what we did.

We decided if we were going to go to the effort we'd do it properly, and so opted for a new set of Koni dampeners (aka shock absorbers) we got from the Bus Depot, and they sure ain't cheap at $500 for a set of 4 (but they are made in The Netherlands). Plus a set of EMPI heavy duty anti-sway bars from The Bus Boys at a reasonable $200 for both front and rear.

A local garage installed 3 of the 4 shocks, but sheared the lower bolt removing the fourth. Oops. The guys at another shop drilled out the sheared bolt and installed the final Koni, plus the front anti-sway. The rear will have to wait til Detroit.

But the result on the handling has been... amazing. Incredible.

We can now cruise comfortably at 65mph (about all the little 1.7L engine can handle), even with a mild cross wind. The buffeting now shifts the bus inches rather than feet and it's easy to stay in the lane. Also the ride is wonderfully smooth yet reassuringly firm when required. Even in a strong gusting side wind, like we experienced in a thunder storm somewhere in Arkansas, I only had to drop the speed down to 55mph to feel safe. It's a totally different driving experience now. Wonderful.

Although by doing both jobs at the same time makes it difficult to know with certainty, I suspect the biggest improvement was from those beautiful Koni shocks. Would just putting new (and much cheaper) OEM shocks have been as good? Maybe, who knows? I didn't want to take the risk of always thinking later 'imaybe if I'd spent the extra $200 for Konis this would be better'. When we put the rear anti-sway bar on and drive it back home in August I'll report on what difference that made, because you can still feel a very slight sway when sitting in the back seat when cruising at top speed, and maybe that'll go too!

Oil & gas mileage
Not too much to report here. We're running 87 unleaded (remember the engine is low compression and was made for standard fuel) and getting an average of 18.4 MPG (ranging from 20 to 17). The better mileage is when Sarah was driving! I've been pleasantly surprised by the oil - it's only used about half a quart of oil so far (roughly 800 miles or so), which I take as a good sign. I'd be more concerned if it wasn't using any oil at all.

Other niggles
Second gear is still a total bitch. Sometimes it's easy on the way up, but just when you think you've cracked it, especially when you've got a pile of traffic behind you, it refuses to go into second making you go back to first and then straight to third. Ah well. If possible, double clutching will get it in on the way down, and shifting up as soon as possible helps on the way up.